david p



(No Model.)

D. P. DAVIS. BALANCE FOR STEAM ENGINE EGQENTRIOS. No; 419,836..Patented. JanLZl, 1890.

\ N. FETERS. Plmlo-Limngmphcy. wnhin tnn. D41.

UNITED I STATES PATENT OFFICE.

DAVID P. DAVIS, OF ALLENDALE, NEWV JERSEY, ASSIGNOR TO THE NEW YORKSAFETY STEAM POlVER COMPANY, OF NEW YORK, N. Y.

BALANCE FOR STEAM -ENGIN E ECCENTRIGS.

SPECIFICATION forming part of Letters Patent No. 419,836, dated January21, 1890. Application filed May 10, 1889. Serial No. 310,271- (Nomodel.)

To all whom it may concern:

Be it known that I, DAVID P. DAVIS, of Allendale, in the county ofBergen and State of New Jersey, have invented an Improved Means forBalancing the VVe'ight of the Eccentrics, Eccentric-Straps, andConnections for Steam-Engines, of which the following is aspecification.

In wheel-governors for automatic engines the centrifugal force of thegovernor weights or balls has been made use of for shifting the positionof the center of the eccentric, and thus Varying its angularity inreference to the center of the shaft and the crank-pin, so as to admitmore or less steam to the cylinder as the load upon the engine isvaried. A device of this character is represented in Letters Patent No.303,711, granted to me August 19, 1884:. In the practical use ofgovernors of this character I have ascertained that after a time more orless wear of the various parts takes place and lost motion is produced,which is multiplied at the eccentric, because of the manner in which itis hung. If the speed of the engine is sufficient, the centrifugalaction keeps the eccentric in position and nothing detrimental occurs;but if the'speed is slow the weight of the eccentric and its connectionscauses them to drop slightly every time they pass the center and a jerkyactionof the valve takes place, causing an unequal distribution of thesteam, and the effect is unpleasant, if not detrimental. By balancingthe weight of the eccentric and its connections this is entirelyovercome, and the result is smooth running at any speed.

In my improvement a counterpoise or balance on the frame of the engineis connected to the eccentriostrap to lessen the wear upon the eccentricand strap, and when used with automatic governors upon the fly-wheel thecounterpoise prevents the looseness and lateral movement of theeccentric and the false or jerky movement of the valve.

In the drawings, Figure 1 is a side elevation. illustrating myimprovement as applied to the eccentric of an engine, and Fig. 2 is anend elevation of the same The main shaft A of the engine is supported inthe bed-frame and bearings 13 in any convenient manner, and theeccentric O is of the proper size and construction, surrounding theshaft A, but not directly connected to the same; and D represents theeccentric-rod. The eccentric O is provided with an arm E, at the end ofwhich is a pivotal connection F to the fly-wheel or belt-wheel G, and Iremark thatthe governor device is so connected to the eccentric as tomove the same laterally and vary the stroke of the valve 5 but thisgovernor mechanism is not represented, as the same may be such as shownin my aforesaid patent, or it may be of any desired character.

My present improvement relates to the device made use of for balancingthe Weight of the eccentric, the strap, and a portion of the weight ofthe eccentric-rod. To effect this I make use of a lever H, pivoted at 2upon the frame or bed B, and from the long arm of this bent lever H alink K extends to the eccentricstrap 0, and it is preferable to fork theend of the link, so that it receives into the fork the strengtheningu'iband hub upon the eccentricstrap 0, and the connecting-bolt 3 passesthrough the forks of the link K and through the hub upon theeccentric-strap O". The spring L is preferably a coiled steel wire orrod connected at its ends to the heads M, and these heads are perforatedin the middle and screwthreaded for the reception of the right and lefthand screw-rods N O, the rod 0 being pivoted at 5 to the short arm ofthe lever H, and the rod N being pivoted at 6 upon the frame or bed B,and there are lock-nuts around the respective screw-rods N and 0,adjacent to the heads M. It will now be understood that the spring Lacts by tension upon the bent lever H to cause the long end of said 1ever and the link K to support the eccentric strap and rod to any desiredextent, and by loosening the lock-nuts and revolving the spring L andheads M the power of the spring L can be varied to whatever extentdesired, and as the eccentric moves the eccentric-rod and the strap 0backward and forward in giving motion to the valve the springL yieldsmore or less and the lever H turns upon its pivot 2, and the linkKswings back and forth by the movement of the eccentric, and inconsequence of the weight of the eccentric being supported through theaction of the spring and connections to the strap of the eccentric sucheccentric will not fall by its weight or give any false movement to thevalve, and a the governor is free to give the proper movement to theeccentric laterally in regulating the throw of the valve.

In engines that run at a slow speed the lever H may be extended andreceive a movable weight, as shown by dotted lines in Fig.

1. The combination, with the laterally-mov-- ing eccentric-strap andeccentric-rod, of the yielding support connected to the frame of theengine and the eccentric-strap, respectively, for sustaining the weightof the eccentric or a portion thereof, substantially as set 1 forth 2.The co mbination with the laterally-moving eccentricstrap andeccentric-rod, of the lever H, spring L, and, link K, such link K beingpivoted to the strap of the eccentric and acting to sustain or partiallysustain the Weight of the eccentric without interfering with itsmovement, substantially as set forth.

3. The combination, with the eccentric, eccentric-rod, and strap, of thecounterpoise lever H, and the link K, connecting the lever to theeccentric-strap, substantially as set forth.

Signed by me this 7th day of May, 1889.

DAVID P. DAVIS.

Witnesses:

GEO. T. 'PINCKNEY, WILLIAM G. Mom

